A multifunctional PEGylated liposomal-encapsulated sunitinib enhancing autophagy, immunomodulation, and safety in renal cell carcinoma

Background: Sunitinib is a multikinase inhibitor used to treat patients with advanced renal cell carcinoma (RCC). However, sunitinib toxicity makes it a double-edged sword. Potent immune modulation by sunitinib extends to nuclear interactions. To address these issues, there is an urgent need for delivery vectors suitable for sunitinib treatment. Methods: We developed PEGylated liposomes as delivery vectors to precisely target sunitinib (lipo-sunitinib) to RCC tumors. Further investigations, including RNA sequencing (RNA-seq), were performed to evaluate transcriptomic changes in these pathways. DiI/DiR-labeled lipo-sunitinib was used for the biodistribution analysis. Flow cytometry and immunofluorescence (IF) were used to examine immune modulation in orthotopic RCC models. Results: The evaluation of results indicated that lipo-sunitinib precisely targeted the tumor site to induce autophagy and was readily taken up by RCC tumor cells. In addition, transcriptomic assays revealed that following lipo-sunitinib treatment, autophagy, antigen presentation, cytokine, and chemokine production pathways were upregulated, whereas the epithelial-mesenchymal transition (EMT) pathway was downregulated. In vivo data provided evidence supporting the inhibitory effect of lipo-sunitinib on RCC tumor progression and metastasis. Flow cytometry further demonstrated that liposunitinib increased the infiltration of effector T cells (Teffs) and conventional type 1 dendritic cells (cDC1s) into the tumor. Furthermore, systemic immune organs such as the tumor-draining lymph nodes, spleen, and bone marrow exhibited upregulated anticancer immunity following lipo-sunitinib treatment. Conclusion: Our findings demonstrated that lipo-sunitinib is distributed at the RCC tumor site, concurrently inducing potent autophagy, elevating antigen presentation, activating cytokine and chemokine production pathways, and downregulating EMT in RCC cells. This comprehensive approach significantly enhanced tumor inhibition and promoted anticancer immune modulation. Graphical Abstract: (Figure presented.)